Techniques for unified synchronization channel design in new radio

ABSTRACT

Various aspects described herein relate to techniques for synchronization channel design and signaling in wireless communications systems (e.g., a 5th Generation (5G) New Radio (NR) system). In an aspect, a method includes identifying a frequency band supported by a user equipment (UE), identifying one or more frequency locations based on the identified frequency band, and the one or more frequency locations are a subset of synchronization raster points used for synchronization signal transmission. The method further includes searching for at least one synchronization signal based on the one or more identified frequency locations.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/837,871 filed Dec. 11, 2017, entitled, TECHNIQUES FOR UNIFIEDSYNCHRONIZATION CHANNEL DESIGN IN NEW RADIO, which claims the benefit ofthe filing date of U.S. Provisional Application Ser. No. 62/433,098,entitled “NEW RADIO (NR) UNIFIED SS/PBCH DESIGN” and filed on Dec. 12,2016, both of which are expressly incorporated by reference herein intheir entirety.

BACKGROUND

Aspects of the present disclosure relate generally to wirelesscommunications, and more particularly, to techniques for synchronizationchannel design and signaling in wireless communications systems (e.g., a5th Generation (5G) New Radio (NR) system).

Wireless communication networks are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, orthogonalfrequency-division multiple access (OFDMA) systems, single-carrierfrequency division multiple access (SC-FDMA) systems, and time divisionsynchronous code division multiple access (TD-SCDMA).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example telecommunication standardis Long Term Evolution (LTE) or LTE-Advanced (LTE-A). However, althoughnewer multiple access systems, such as an LTE or LTE-A system, deliverfaster data throughput than older technologies, such increased downlinkrates have triggered a greater demand for higher-bandwidth content, suchas high-resolution graphics and video, for use on or with mobiledevices. As such, demand for bandwidth, higher data rates, bettertransmission quality as well as better spectrum utilization, and lowerlatency on wireless communications systems continues to increase.

The 5G NR communications technology, used in a wide range of spectra, isenvisaged to expand and support diverse usage scenarios and applicationswith respect to current mobile network generations. In an aspect, 5G NRcommunications technology includes, for example: enhanced mobilebroadband (eMBB) addressing human-centric use cases for access tomultimedia content, services and data; ultra-reliable low-latencycommunications (URLLC) with strict requirements, especially in terms oflatency and reliability; and massive machine type communications (mMTC)for a very large number of connected devices and typically transmittinga relatively low volume of non-delay-sensitive information.

In addition, 5G NR communications technology is part of a continuousmobile broadband evolution promulgated by the Third GenerationPartnership Project (3GPP) to meet new requirements associated withlatency, reliability, security, scalability (e.g., with Internet ofThings (IoT)), and other requirements. Some aspects of 5G NRcommunications technology may be based on LTE standards. As the demandfor mobile broadband access continues to increase, there exists a needfor further improvements in 5G communications technology and beyond.Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

Accordingly, due to the requirements for increased data rates, lowerlatency, higher capacity, and better resource utilization, currentsynchronization signal processing solutions may not provide a desiredlevel of speed or customization for efficient operation. As such, newapproaches may be desirable to improve the signaling andsynchronization, enhance system reliability, and improve user experiencein wireless communications.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

According to an example, the present disclosure includes a methodrelated to synchronization channel design and signaling in wirelesscommunications is provided. In an aspect, the method includesidentifying a frequency band in a subset of frequency bands supported bya user equipment (UE), identifying a synchronization numerology used forthe subset of frequency bands, and searching for at least onesynchronization signal having the identified synchronization numerologyat the identified frequency band.

According to another example, a method related to synchronizationchannel design and signaling in wireless communications is provided. Inan aspect, the method includes identifying a frequency band supported bya UE, identifying one or more frequency locations based on theidentified frequency band, and the one or more frequency locations are asubset of synchronization raster points used for synchronization signaltransmission. The method further includes searching for at least onesynchronization signal based on the one or more identified frequencylocations.

In a further aspect, an apparatus for wireless communications isprovided that includes a transceiver (e.g., a transmitter and/or areceiver), a memory configured to store instructions, and one or moreprocessors communicatively coupled with the transceiver and the memory.The one or more processors are configured to execute the instructions toperform the operations of the methods described herein. In anotheraspect, an apparatus for wireless communication is provided thatincludes means for performing the operations of the methods describedherein. In yet another aspect, a computer-readable medium (e.g., anon-transitory computer-readable medium) is provided and includes codeexecutable by one or more processors to perform the operations of themethods described herein.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate a fuller understanding of aspects describedherein, reference is now made to the accompanying drawings, in whichlike elements are referenced with like numerals. These drawings shouldnot be construed as limiting the present disclosure, but are intended tobe illustrative only.

FIG. 1 is a schematic diagram of a wireless communication networkincluding at least one user equipment (UE) or a base station having asynchronization signal management component configured or operatedaccording to one or more of the presently described aspects;

FIG. 2 includes frequency bands having one or more channel raster forpossible transmission of synchronization signals and a physicalbroadcast channel (PBCH), according to one or more of the presentlydescribed aspects;

FIG. 3A is a first example of a frame structure scheme forsynchronization signals, according to one or more of the presentlydescribed aspects;

FIG. 3B is a second example of a frame structure scheme forsynchronization signals, according to one or more of the presentlydescribed aspects;

FIG. 3C is an example of a synchronization signal block, according toone or more of the presently described aspects;

FIG. 4 is a flow diagram of an example method performed by a UE forsearching for synchronization signals in a subset of frequency bands,according to one or more of the presently described aspects;

FIG. 5 is a flow diagram of a first example method performed by a UE forsynchronization channel design and signaling, according to one or moreof the presently described aspects;

FIG. 6 is a flow diagram of a second example method performed by a UEfor synchronization channel design and signaling according to one ormore of the presently described aspects;

FIG. 7 is a flow diagram of a first example method performed by a basestation for synchronization channel design and signaling, according toone or more of the presently described aspects;

FIG. 8 is a flow diagram of a second example method performed by a basestation for synchronization channel design and signaling, according toone or more of the presently described aspects;

FIG. 9 is a schematic diagram of example components of a UE forsynchronization channel design and signaling, according to one or moreof the presently described aspects.

FIG. 10 is a schematic diagram of example components of a base stationfor synchronization channel design and signaling, according to one ormore of the presently described aspects.

DETAILED DESCRIPTION

In a wireless communication network, before a user equipment (UE) maycommunicate with a network, the UE may find and acquire synchronizationto one or more cells within the network, which in some examples, may bereferred to as a “cell search.” In an aspect, the cell search mayconsist of acquisition of frequency and symbol synchronization to acell, acquisition of frame timing of the cell and determination ofphysical-layer cell identity of the cell. Thus, the cell search mayenable the UE to acquire physical cell identification (ID), time slotand frame synchronization, which allow the UE to read system informationblocks from a particular network. In order to assist the cell search,two special signals are transmitted on each downlink component carrier:primary synchronization signal (PSS) and secondary synchronizationsignal (SSS). The time-domain positions of the synchronization signalswithin the frame may differ depending on whether the cell is operatingin FDD or TDD. The differences between FDD and TDD in PSS (or SSS)time-domain frame structure allow for the UE to detect duplex mode ofthe acquired carrier. In some aspects, the UE may search the PSS or SSSby tuning a radio to different frequency channels depending upon whichbands the UE supports. However, searching for the synchronizationsignals may be a resource intensive endeavor.

Accordingly, features of the present disclosure solve theabove-identified problem by, for example, implementing techniques orschemes that reduce the time for searching synchronization signalsperformed by the UE. In some aspects, the UE may search a subset offrequency bands or locations that are identified by the UE. In someexamples, the features of the present disclosure may reduce the searchlatency and/or UE power consumptions at the UE.

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details. Additionally, the term“component” as used herein may be one of the parts that make up asystem, may be hardware, firmware, and/or software stored on acomputer-readable medium, and may be divided into other components.

It should be noted that the techniques described herein may be used forvarious wireless communication networks such as CDMA, TDMA, FDMA, OFDMA,SC-FDMA, and other systems. The terms “system” and “network” are oftenused interchangeably. A CDMA system may implement a radio technologysuch as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc.CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856)is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data(HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants ofCDMA. A TDMA system may implement a radio technology such as GlobalSystem for Mobile Communications (GSM). An OFDMA system may implement aradio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA(E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM™, etc. UTRA and E-UTRA are part of Universal MobileTelecommunication System (UMTS). 3GPP Long Term Evolution (LTE) andLTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA,E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). CDMA2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). The techniques describedherein may be used for the systems and radio technologies mentionedabove as well as other systems and radio technologies, includingcellular (e.g., LTE) communications over a shared radio frequencyspectrum band. The description below, however, describes an LTE/LTE-Asystem for purposes of example, and LTE terminology is used in much ofthe description below, although the techniques are applicable beyondLTE/LTE-A applications (e.g., to 5G networks or other next generationcommunication systems).

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

Each of the aspects described above are performed or implemented inconnection with FIGS. 1-10, which are described in more detail below.

Referring to FIG. 1, in accordance with various aspects of the presentdisclosure, an example wireless communication network 100 includes atleast one UE 110 with a modem 140 having a synchronization signalmanagement component 150 that performs cell search by identifyinglocations for synchronization signal (e.g., a PSS, an SSS, or a signalover PBCH) based on the band category supported by the UE 110. In someexamples, the wireless communication network 100 may include at leastone base station 105 with a modem 160 having a synchronizationmanagement component 170 that performs synchronization signal (e.g., aPSS, an SSS, or a signal over PBCH) management and signaling based onfrequency bands supported by the UE 110. In an example, thesynchronization management component 170 may be configured to generatesynchronization signals, and transmit the synchronization signals to oneor more UE 110.

The wireless communication network 100 may include one or more basestations 105, one or more UEs 110, and a core network 115. The corenetwork 115 may provide user authentication, access authorization,tracking, internet protocol (IP) connectivity, and other access,routing, or mobility functions. The base stations 105 may interface withthe core network 115 through backhaul links 120 (e.g., S1, etc.). Thebase stations 105 may perform radio configuration and scheduling forcommunication with the UEs 110, or may operate under the control of abase station controller (not shown). In various examples, the basestations 105 may communicate, either directly or indirectly (e.g.,through core network 115), with one another over backhaul links 125(e.g., X1, etc.), which may be wired or wireless communication links.

The base stations 105 may wirelessly communicate with the UEs 110 viaone or more base station antennas. Each of the base stations 105 mayprovide communication coverage for a respective geographic coverage area130. In some examples, base stations 105 may be referred to as a basetransceiver station, a radio base station, an access point, an accessnode, a radio transceiver, a NodeB, eNodeB (eNB), gNB, Home NodeB, aHome eNodeB, a relay, or some other suitable terminology. The geographiccoverage area 130 for a base station 105 may be divided into sectors orcells making up only a portion of the coverage area (not shown). Thewireless communication network 100 may include base stations 105 ofdifferent types (e.g., macro base stations or small cell base stations,described below). Additionally, the plurality of base stations 105 mayoperate according to different ones of a plurality of communicationtechnologies (e.g., 5G (New Radio or “NR”), fourth generation (4G)/LTE,3G, Wi-Fi, Bluetooth, etc.), and thus there may be overlappinggeographic coverage areas 130 for different communication technologies.

In some examples, the wireless communication network 100 may be orinclude one or any combination of communication technologies, includinga NR or 5G technology, a Long Term Evolution (LTE) or LTE-Advanced(LTE-A) or MuLTEfire technology, a Wi-Fi technology, a Bluetoothtechnology, or any other long or short range wireless communicationtechnology. In LTE/LTE-A/MuLTEfire networks, the term evolved node B(eNB) may be generally used to describe the base stations 105, while theterm UE may be generally used to describe the UEs 110. The wirelesscommunication network 100 may be a heterogeneous technology network inwhich different types of eNBs provide coverage for various geographicalregions. For example, each eNB or base station 105 may providecommunication coverage for a macro cell, a small cell, or other types ofcell. The term “cell” is a 3GPP term that can be used to describe a basestation, a carrier or component carrier associated with a base station,or a coverage area (e.g., sector, etc.) of a carrier or base station,depending on context.

A macro cell may generally cover a relatively large geographic area(e.g., several kilometers in radius) and may allow unrestricted accessby UEs 110 with service subscriptions with the network provider.

A small cell may include a relative lower transmit-powered base station,as compared with a macro cell, that may operate in the same or differentfrequency bands (e.g., licensed, unlicensed, etc.) as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 110 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessand/or unrestricted access by UEs 110 having an association with thefemto cell (e.g., in the restricted access case, UEs 110 in a closedsubscriber group (CSG) of the base station 105, which may include UEs110 for users in the home, and the like). An eNB for a macro cell may bereferred to as a macro eNB. An eNB for a small cell may be referred toas a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB maysupport one or multiple (e.g., two, three, four, and the like) cells(e.g., component carriers).

The communication networks that may accommodate some of the variousdisclosed examples may be packet-based networks that operate accordingto a layered protocol stack and data in the user plane may be based onthe IP. A user plane protocol stack (e.g., packet data convergenceprotocol (PDCP), radio link control (RLC), MAC, etc.), may performpacket segmentation and reassembly to communicate over logical channels.For example, a MAC layer may perform priority handling and multiplexingof logical channels into transport channels. The MAC layer may also usehybrid automatic repeat/request (HARQ) to provide retransmission at theMAC layer to improve link efficiency. In the control plane, the RRCprotocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 110 and the base stations 105. The RRCprotocol layer may also be used for core network 115 support of radiobearers for the user plane data. At the physical (PHY) layer, thetransport channels may be mapped to physical channels.

The UEs 110 may be dispersed throughout the wireless communicationnetwork 100, and each UE 110 may be stationary or mobile. A UE 110 mayalso include or be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology. A UE 110 may be a cellular phone, asmart phone, a personal digital assistant (PDA), a wireless modem, awireless communication device, a handheld device, a tablet computer, alaptop computer, a cordless phone, a smart watch, a wireless local loop(WLL) station, an entertainment device, a vehicular component, acustomer premises equipment (CPE), or any device capable ofcommunicating in wireless communication network 100. Additionally, a UE110 may be Internet of Things (IoT) and/or machine-to-machine (M2M) typeof device, e.g., a low power, low data rate (relative to a wirelessphone, for example) type of device, that may in some aspects communicateinfrequently with wireless communication network 100 or other UEs. A UE110 may be able to communicate with various types of base stations 105and network equipment including macro eNBs, small cell eNBs, macro gNBs,small cell gNBs, relay base stations, and the like.

The UE 110 may be configured to establish one or more wirelesscommunication links 135 with one or more base stations 105. The wirelesscommunication links 135 shown in wireless communication network 100 maycarry uplink (UL) transmissions from a UE 110 to a base station 105, ordownlink (DL) transmissions, from a base station 105 to a UE 110. Thedownlink transmissions may also be called forward link transmissionswhile the uplink transmissions may also be called reverse linktransmissions. Each wireless communication link 135 may include one ormore carriers, where each carrier may be a signal made up of multiplesub-carriers (e.g., waveform signals of different frequencies) modulatedaccording to the various radio technologies described above. Eachmodulated signal may be sent on a different sub-carrier and may carrycontrol information (e.g., reference signals, control channels, etc.),overhead information, user data, etc. In an aspect, the wirelesscommunication links 135 may transmit bidirectional communications usingfrequency division duplex (FDD) (e.g., using paired spectrum resources)or time division duplex (TDD) operation (e.g., using unpaired spectrumresources). Frame structures may be defined for FDD (e.g., framestructure type 1) and TDD (e.g., frame structure type 2). Moreover, insome aspects, the wireless communication links 135 may represent one ormore broadcast channels.

In some aspects of the wireless communication network 100, base stations105 or UEs 110 may include multiple antennas for employing antennadiversity schemes to improve communication quality and reliabilitybetween base stations 105 and UEs 110. Additionally or alternatively,base stations 105 or UEs 110 may employ multiple input multiple output(MIMO) techniques that may take advantage of multi-path environments totransmit multiple spatial layers carrying the same or different codeddata.

Wireless communication network 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 110 may be configured with multipledownlink CCs and one or more uplink CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers. Thebase stations 105 and UEs 110 may use spectrum up to Y MHz (e.g., Y=5,10, 15, or 20 MHz) bandwidth per carrier allocated in a carrieraggregation of up to a total of Yx MHz (x=number of component carriers)used for transmission in each direction. The carriers may or may not beadjacent to each other. Allocation of carriers may be asymmetric withrespect to DL and UL (e.g., more or less carriers may be allocated forDL than for UL). The component carriers may include a primary componentcarrier and one or more secondary component carriers. A primarycomponent carrier may be referred to as a primary cell (PCell) and asecondary component carrier may be referred to as a secondary cell(SCell).

The wireless communications network 100 may further include basestations 105 operating according to Wi-Fi technology, e.g., Wi-Fi accesspoints, in communication with UEs 110 operating according to Wi-Fitechnology, e.g., Wi-Fi stations (STAs) via communication links in anunlicensed frequency spectrum (e.g., 5 GHz). When communicating in anunlicensed frequency spectrum, the STAs and AP may perform a clearchannel assessment (CCA) or listen before talk (LBT) procedure prior tocommunicating in order to determine whether the channel is available.

Additionally, one or more of base stations 105 and/or UEs 110 mayoperate according to a NR or 5G technology referred to as millimeterwave (mmW or mmwave) technology. For example, mmW technology includestransmissions in mmW frequencies and/or near mmW frequencies. Extremelyhigh frequency (EHF) is part of the radio frequency (RF) in theelectromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and awavelength between 1 millimeter and 10 millimeters. Radio waves in thisband may be referred to as a millimeter wave. Near mmW may extend downto a frequency of 3 GHz with a wavelength of 100 millimeters. Forexample, the super high frequency (SHF) band extends between 3 GHz and30 GHz, and may also be referred to as centimeter wave. Communicationsusing the mmW and/or near mmW radio frequency band has extremely highpath loss and a short range. As such, base stations 105 and/or UEs 110operating according to the mmW technology may utilize beamforming intheir transmissions to compensate for the extremely high path loss andshort range.

FIG. 2 includes frequency bands 200 having one or more channel raster(s)212 for possible transmission of synchronization signals and a physicalbroadcast channel (PBCH). In some aspects, a channel raster 212 may beused to define the channel spacing between two neighboring channels. Insome examples, a synchronization channel raster 214 may be used toidentify possible frequency locations for transmitting thesynchronization signals (e.g., PSS, SSS) or PBCH. In an example,synchronization channel raster 214 may be the channel spacing betweenfrequency location 216 and frequency location 218, and the channelspacing between frequency location 218 and frequency location 220. Inthis example, each of the frequency locations 216, 218, and 220indicates a frequency that carries at least a synchronization signal(e.g., PSS, SSS) or PBCH.

FIG. 3A is an example of a frame structure scheme 300 for signalsynchronization in accordance with aspects of the present disclosure. Inan example, a frame structure 302 may include a 1-ms slot in time domainand 15 kHz in frequency domain. The frame structure 302 may beTDD-based, and may include fourteen (14) symbols. In an aspect, withinthe 14 symbols, there may be two (2) DL common bursts 314 (e.g., in thefirst 2 symbols), two (2) UL common bursts 318 (e.g., in the last 2symbols), and ten (10) data or control symbols 316 in the middle (DL orUL) of the frame structure 302. In an aspect, a synchronization signalblock 308 may include four (4) symbols for PBCH, SSS, PSS, and PBCH, asshown in FIG. 3A. In this example, the synchronization signal block 308is at a frequency band in the first band category (e.g., in Table 1),and may have a 2.16 MHz synchronization signal bandwidth with a 15 kHzsynchronization numerology or channel spacing.

In another example, a frame structure 304 may include a 500-μs slot intime domain and 30 kHz in frequency domain. The frame structure 304 maybe TDD-based, and may include 14 symbols. In an aspect, within the 14symbols, there may be 2 DL common bursts 314 (e.g., in the first 2symbols), 2 UL common bursts 318 (e.g., in the last 2 symbols), and 10data or control symbols 316 in the middle (DL or UL) of the framestructure 304. In an aspect, a synchronization signal block 310 mayinclude eight (8) symbols for PBCH (2 symbols), SSS (2 symbols), PSS (2symbols), and PBCH (2 symbols), as shown in FIG. 3A. In this example,the synchronization signal block 310 may be at a frequency band in thefirst band category (e.g., in Table 1), and may have a 2.16 MHzsynchronization signal bandwidth with a 15 kHz synchronizationnumerology or channel spacing.

In an example, a frame structure 306 may include a 250-μs slot in timedomain and 60 kHz in frequency domain. The frame structure 306 may beTDD-based, and may include 14 symbols. In an aspect, within the 14symbols, there may be 2 DL common bursts 314 (e.g., in the first 2symbols), 2 UL common bursts 318 (e.g., in the last 2 symbols), and 10data or control symbols 316 in the middle (DL or UL) of the framestructure 312. In an aspect, a synchronization signal block 312 mayinclude 8 symbols for PBCH (2 symbols), SSS (2 symbols), PSS (2symbols), and PBCH (2 symbols), as shown in FIG. 3A. In this example,the synchronization signal block 312 may be at a frequency band in thesecond band category (e.g., in Table 1), and may have a 4.32 MHzsynchronization signal bandwidth with a 30 kHz synchronizationnumerology or channel spacing.

In some aspects, design parameters for synchronization channel designand signaling based on different frequency bands of the presentdisclosure are in accordance with Table 1 below. In an aspect, the framestructure scheme 300 may use one or more parameters in Table 1. Forexample, the synchronization signal block 308 or 310 may use one or moreparameters in the first band category (e.g., 2.16 MHz synchronizationsignal bandwidth with 15 kHz synchronization numerology), and thesynchronization signal block 312 may use one or more parameters in thesecond band category (e.g., 4.32 MHz synchronization signal bandwidthwith 30 kHz synchronization numerology). In some examples, eachfrequency band may use a respective synchronization numerology. In somecases, a 60 kHz frame structure (FS) (e.g., the frame structure 306) maybe defined with a minimum system bandwidth of 10 MHz only for the secondband category.

TABLE 1 Design parameters for synchronization channel design andsignaling based on two different frequency bands 1^(st) Band 2^(nd) BandDesign parameters Category Category Min. system bandwidth (MHz) 5 10Sync channel raster (MHz) 1.8 3.6 Sync bandwidth limit (MHz) 2.7 5.4Sync bandwidth (MHz) 2.16 4.32 Sync numerology (kHz) 15 30 Number oftones for SS 128 128 Number of tones for PBCH 128 128 Number of PSSsymbols 1 1 Number of SSS symbols 1 (dual port) 1 (dual port) Number ofPBCH symbols 2 (dual port) 2 (dual port) PBCH DMRS SSS SSS

In an aspect, a method of wireless communications including techniquesfor minimizing synchronization signal search performed by a UE (e.g., UE110). In some aspects, the UE may search a subset of frequency bandsbased on the band category supported by the UE. In contrast toconventional methods of performing “blind searching,” features of thepresent disclosure allow the UE to perform a limited or reduced searchesfor the synchronization signals based on the frequency bands supportedor identified by the UE. In a non-limiting example, two band categoriesmay be provided (e.g., a first band category and a second band categoryin Table 1). In an example, the first category may consist of frequencybands which support the deployments with a minimum system bandwidth of 5MHz. The second band category may consist of frequency bands whichsupport the deployments with a minimum system bandwidth of at least 10MHz.

Accordingly, in an aspect, if the UE belongs to the first band categoryin Table 1, the UE may only search for synchronization signals or PBCHswith a first synchronization numerology (e.g., 15 kHz). In anotheraspect, if the band belongs to the second band category, the UE may onlysearch for synchronization signals or PBCHs with a secondsynchronization numerology (e.g., 30 kHz). In some examples, the firstband category may include data or control channel numerology of 15 kHzor 30 kHz. In some cases, for the second band category, the data orcontrol channel numerology may be one or multiples of 15 kHz (e.g., 15kHz, 30 kHz, or 60 kHz).

In another example, for the first band category, synchronization signallocations may be specified in the specification of a wirelesscommunication standard. Alternatively, in another example, asynchronization channel raster may be equal to or larger than a channelraster. In some cases, a synchronization channel raster is used todefine possible frequency locations for transmitting the synchronizationsignals or PBCHs.

In an aspect, for the second band category in Table 1, thesynchronization channel raster may be a baseline synchronization channelraster (e.g., at least 3.6 MHz). In another aspect, for bands with widefrequency bandwidths (e.g., 5 GHz band with 700 MHz availablebandwidth), the synchronization channel raster may be decimated to havea larger synchronization channel raster than the baselinesynchronization channel raster. For example, a frequency band having afrequency bandwidth that is larger than a minimum channel bandwidth(e.g., 5 MHz) may be considered as having a wide frequency bandwidth(e.g., 10 or 20 MHz). In some aspects, the decimation factor may bespecified in the specification of a wireless communications standard.

In yet another example, different UE categories for differentsynchronization signal or PBCH design may be provided. For example, UEcategory 1 may support synchronization signal or PBCH design for thefirst band category only. In this case, the network (or a base station)may send the first band category synchronization signal or PBCH only. UEcategory 2 may support synchronization signal or PBCH design for thesecond band category only. As such, the network may send the second bandcategory synchronization signal or PBCH only. In yet further example,the UE category 3 may support synchronization signal or PBCH design forboth first band category and second band category. In some examples, thenetwork may send both first band category synchronization signal or PBCHand band category synchronization signal or PBCH to the UE.

In accordance with a first implementation, the UE (e.g., UE 110) may notperform blind searching of the entire frequency band. Instead, forexample, if the determined or identified frequency band belongs to thefirst band category, the UE may only search for synchronization signalsor PBCHs with 15 kHz synchronization numerology. In another example, ifthe determined or identified frequency band belongs to the second bandcategory, the UE may only search for synchronization signals or PBCHswith 30 kHz synchronization numerology. In some examples, for the firstband category, the data or control channel numerology may be 15 kHz or30 kHz. In some cases, for the second band category, the data or controlchannel numerology may be 15 kHz, 30 kHz, or 60 kHz.

In some aspects, the parameters configurations may vary based on thevarious band categories as illustrated in Table 2 below. In someexamples, SSS and PBCH may be on the same ports. In some cases, PSS maybe not necessarily on the same ports as SSS or PBCH.

TABLE 2 Design parameters for synchronization channel design andsignaling based on three different frequency bands Below 6 Below 6 GHz(1^(st) GHz (2^(nd) Above 6 Design parameters Band Cat.) Band Cat.) GHzMin system bandwidth 5 10 80 (MHz) Sync channel raster (MHz) 1.8 3.6 36Sync bandwidth upperbound 2.7 5.4 36 (MHz) Sync bandwidth (MHz) 2.164.32 34.56 Sync numerology (kHz) 15 30 240 Number of tones for SS 128128 128 Number of tones for PBCH 128 128 128 Number of PSS symbols 1 1 1Number of SSS symbols 1 (dual port) 1 (dual port) 1 (dual port) Numberof PBCH symbols 2 (dual 2 (dual 2 (dual port SFBC) port SFBC) port SFBC)PBCH DMRS SSS SSS SSS SS periodicity (ms) 5 5 5 PBCH TTI (ms) 40 (repeat40 (repeat 40 every 10 ms) every 10 ms) MIB size (including 16 bits 4040 >40 CRC) (bits)

In accordance with a second implementation, supplementarysynchronization locations may be identified. Particularly, for the firstband category (e.g., frequency bands with minimum system bandwidth of 5MHz), the UE (e.g., UE 110) may perform synchronization signal or PBCHsearch based on one of two options. In the first option, thesynchronization channel raster may be equal to a channel raster. In thesecond option, the synchronization frequency locations may be specifiedin the specification of a wireless communications standard. In someexamples, when the synchronization signal or channel bandwidth is closeto the minimum channel bandwidth, only a subset of synchronizationraster points may be selected for synchronization signal transmission.In some cases, selecting a subset of synchronization raster points forsynchronization signal transmission may reduce the search latency and/orUE power consumption at the UE. In some cases, the subset ofsynchronization raster points is known to both the network (e.g., a basestation 105) and the UE (e.g., a UE 110).

In an aspect, for the second band category, the synchronization channelraster may be at least 3.6 MHz (or a baseline synchronization raster).In an example, to locate or identify supplementary synchronizationlocations, for frequency bands with wide frequency bandwidth, e.g., 5GHz band with about 700 MHz available bandwidth, the synchronizationraster points (e.g., defined based on the baseline synchronizationraster) may be decimated to have a larger synchronization raster, forexample, a larger synchronization raster than the baselinesynchronization raster. In some examples, the minimum channel bandwidthand synchronization signal/channel bandwidth may be identified ordetermined by the UE 110. The upper bound of the synchronization rastermay be the difference between the minimum channel bandwidth andsynchronization signal/channel bandwidth. In some cases, thesynchronization raster may be equal to the minimum channel bandwidth(e.g., 5 MHz). In some examples, for some frequency bands with a minimumchannel bandwidth larger than 5 MHz, the decimation may be performed orconfigured. In some examples, the decimation factor may be specified inthe specification of a wireless communications standard.

In some examples, the parameter values for the first implementation andsecond implementation may be as defined in Table 3 below.

TABLE 3 Design parameters for searching synchronization frequencylocations 1^(st) Band 2^(nd) Band Design parameters Category CategoryMin. system bandwidth (MHz) 5 10 Sync channel raster (MHz) Predetermined3.6 Sync bandwidth limit (MHz) Predetermined 5.4 Sync bandwidth (MHz)4.32 Sync numerology (kHz) 30 Number of tones for SS 128 Number of tonesfor PBCH 128 Number of PSS symbols 1 Number of SSS symbols 1 (dual port)Number of PBCH symbols 2 (dual port) PBCH DMRS SSS SS periodicity (ms) 5PBCH TTI (ms) 40 (repeat every 10 ms) MIB size (including 16 bits CRC)40 (bits)

FIG. 3B is an example of a frame structure scheme 330 for signalsynchronization in accordance with a third implementation of the presentdisclosure. In an aspect, one or more synchronization signals or PBCHsmay be included in 15 kHz with slot bundling as shown in FIG. 3B. In anexample, similar to the frame structure scheme 300, a frame structure302 may include a 1-ms slot in time domain and 15 kHz in frequencydomain. The frame structure 302 may be TDD-based, and may include 14symbols. In an aspect, within the 14 symbols, there may be 2 DL commonbursts 314 (e.g., in the first 2 symbols), 2 UL common bursts 318 (e.g.,in the last 2 symbols), and 10 data or control symbols 316 in the middle(DL or UL) of the frame structure 302. In an aspect, a synchronizationsignal block 308 may include 4 symbols for PBCH, SSS, PSS, and PBCH, asshown in FIG. 3B. In this example, the synchronization signal block 308may be at a frequency band that below 6 GHz, and may have 2.16 MHzsynchronization signal bandwidth with 15 kHz synchronization numerologyor channel spacing (e.g., see parameters in Table 4).

In another example, similar to the frame structure scheme 300, a framestructure 304 may include a 500-μs slot in time domain and 30 kHz infrequency domain. The frame structure 304 may be TDD-based, and mayinclude 14 symbols. In an aspect, within the 14 symbols, there may be 2DL common bursts 314 (e.g., in the first 2 symbols), 2 UL common bursts318 (e.g., in the last 2 symbols), and 10 data or control symbols 316 inthe middle (DL or UL) of the frame structure 304. In an aspect, asynchronization signal block 310 may include 8 symbols for PBCH (2symbols), SSS (2 symbols), PSS (2 symbols), and PBCH (2 symbols), asshown in FIG. 3B. In this example, the synchronization signal block 310may be at a frequency band that below 6 GHz, and may have 2.16 MHzsynchronization signal bandwidth with 15 kHz synchronization numerologyor channel spacing (e.g., see parameters in Table 4).

In an example, a frame structure 332 may include a 500-μs slot in timedomain and 60 kHz in frequency domain. The frame structure 332 may beTDD-based, and may include two (2) regular slots, where each slot hasfourteen (14) symbols. In an aspect, the frame structure 332 may includea combined slot with two (2) or more regular slots. In this example, two(2) regular 14-symbol slots are combined or bundled, and the 500-μs slotwith the frame structure 332 includes twenty-eight (28) symbols (e.g.,28 OFDM symbols). In an aspect, within the 28 symbols, there may be 2 DLcommon bursts 314 (e.g., in the first 2 symbols), 2 UL common bursts 318(e.g., in the last 2 symbols), and twenty-four (24) data or controlsymbols 316 in the middle (DL or UL) of the 500-μs slot with the framestructure 332. In some cases, there are no DL or UL common bursts in themiddle of the slot with the frame structure 332. In this example, no DLor UL common bursts in the middle of the slot that has 500 μs in timedomain and 60 kHz in frequency domain. In an aspect, a synchronizationsignal block 334 may include sixteen (16) symbols for PBCH (4 symbols),SSS (4 symbols), PSS (4 symbols), and PBCH (4 symbols), as shown in FIG.3B. In this example, the synchronization signal block 312 may be at afrequency band that below 6 GHz, and may have 2.16 MHz synchronizationsignal bandwidth with 15 kHz synchronization numerology or channelspacing (e.g., see parameters in Table 4).

In some examples, the parameters for the third implementation may be inaccordance with Table 4:

TABLE 4 Design parameters for synchronization channel design andsignaling at frequency bands below 6 GHz Design parameters Below 6 GHzMin. system bandwidth (MHz) 5 Sync channel raster (MHz) 1.8 Syncbandwidth limit (MHz) ≤2.7 Sync bandwidth (MHz) 2.16 Sync numerology(kHz) 15 Number of tones for SS 128 Number of tones for PBCH 128 Numberof PSS symbols 1 Number of SSS symbols 1 (dual port) Number of PBCHsymbols 2 (dual port) PBCH DMRS SSS

In some examples, one or more synchronization signals or PBCHs may havea respective synchronization numerology with slot bundling as shown inTable 5. For example, the design parameters for the synchronizationsignals or PBCHs that are below 6 GHz band may be different than theparameters used for above 6 GHz as illustrated in Table 5. In anexample, SSS and PBCH may be on the same ports. In an aspect, PSS maynot be necessarily on the same ports as SSS or PBCH.

TABLE 5 Design parameters for synchronization channel design andsignaling (below and above 6 GHz band) Band Below Band Above Designparameters 6 GHz 6 GHz Min. system bandwidth (MHz) 5 80 Sync channelraster (MHz) 1.8 36 Sync bandwidth upperbound 2.7 36 (MHz) Syncbandwidth (MHz) 2.16 34.56 Sync numerology (kHz) 15 240 Number of tonesfor SS 128 128 Number of tones for PBCH 128 128 Number of PSS symbols 11 Number of SSS symbols 1 (dual port) 1 (dual port) Number of PBCHsymbols 2 (dual 2 (dual port SFBC) port SFBC) PBCH DMRS SSS SSS SSperiodicity (ms) 5 5 PBCH TTI (ms) 40 (repeat 40 every 10 ms) MIB size(including 16 40 >40 bits CRC) (bits)

FIG. 3C is an example of a synchronization channel structure 350 inaccordance with the implementations of the present disclosure. In anaspect, a synchronization signal block (e.g., synchronization signalblock 308, 310, 312, or 334) may include a PSS 352 (12 resource blocks(RBs)), a PBCH 354 (20 RBs), a PBCH 356 (4 RBs), a PBCH 360 (4 RBs), aPBCH 358 (20 RBs), and an SSS 362 (12 RBs), as shown in FIG. 3C. In thisexample, the synchronization signal block may be at a frequency band. Inan aspect, a synchronization channel raster (e.g., synchronizationchannel raster 214) may be used to identify possible frequency locationsfor transmitting or searching for the synchronization signal block whichincludes one or more synchronization signals (e.g., PSS, SSS) or PBCH,for example, PSS 352, PBCH 354, PBCH 356, PBCH 360, PBCH 358, and/or SSS362.

FIG. 4 is a flow diagram of an example of a method 400 of the presentdisclosure for searching a subset of frequency bands. The method 400 maybe performed by a UE 110 and more particularly by the synchronizationsignal management component 150 described with reference to FIGS. 1 and9. For example, one or more of the processors 912, the memory 916, themodem 140, the synchronization signal management component 150,frequency band component 152, signal searching component 154,synchronization numerology component 156, and/or frequency locationcomponent 158, may be configured to perform aspects of the method 400.

At block 402, the method 400 may include determining a frequency bandcategory supported by a UE. In an aspect, for example, along with one ormore of the processors 912, the memory 916, the modem 140, and/or thetransceiver 902, the synchronization signal management component 150,and/or frequency band component 152 may be configured to determine afrequency band category supported by the UE.

At block 404, the method 400 may include identifying a synchronizationsignal (e.g., PSS or SSS) location in a frequency band based on thedetermination. In an aspect, for example, along with one or more of theprocessors 912, the memory 916, the modem 140, and/or the transceiver902, the synchronization signal management component 150, frequency bandcomponent 152, and/or frequency location component 158 may be configuredto identify a synchronization signal (e.g., PSS or SSS) or PBCH locationbased on the frequency band determined at block 402.

At block 406, the method 400 may include searching a subset of thefrequency band for synchronization signal based on the identification ofthe synchronization signal location. In an aspect, for example, alongwith one or more of the processors 912, the memory 916, the modem 140,and/or the transceiver 902, the synchronization signal managementcomponent 150, frequency band component 152, signal searching component154, and/or frequency location component 158 may be configured to searcha subset of the frequency band used for synchronization signal(s) basedon the synchronization signal location identified at block 404.

At block 408, the method 400 may optionally include establishingcommunication with a base station based on the synchronization signal.In an aspect, for example, along with one or more of the processors 912,the memory 916, the modem 140, and/or the transceiver 902, thesynchronization signal management component 150 may be configured toestablish communications with a base station based on thesynchronization signal.

FIG. 5 is a flow diagram of an example method 500 of the presentdisclosure for synchronization channel design and signaling. The method500 may be performed by a UE 110 and more particularly by thesynchronization signal management component 150 described with referenceto FIGS. 1 and 9. For example, one or more of the processors 912, thememory 916, the modem 140, the synchronization signal managementcomponent 150, frequency band component 152, signal searching component154, synchronization numerology component 156, and/or frequency locationcomponent 158, may be configured to perform aspects of the method 500.

At block 502, the method 500 may include identifying a frequency band ina subset of frequency bands supported by a UE. In an aspect, forexample, along with one or more of the processors 912, the memory 916,the modem 140, and/or the transceiver 902, the synchronization signalmanagement component 150, and/or frequency band component 152 may beconfigured to identify or determine a frequency band in a subset offrequency bands that are supported by the UE 110.

At block 504, the method 500 may include identifying a synchronizationnumerology used for the subset of frequency bands. In an aspect, forexample, along with one or more of the processors 912, the memory 916,the modem 140, and/or the transceiver 902, the synchronization signalmanagement component 150, frequency band component 152, and/orsynchronization numerology component 156 may be configured to identify asynchronization numerology used for the frequency band identified atblock 502 and/or the subset of frequency bands supported by the UE 110.

At block 506, the method 500 may include searching for at least onesynchronization signal having the identified synchronization numerologyat the identified frequency band. In an aspect, for example, along withone or more of the processors 912, the memory 916, the modem 140, and/orthe transceiver 902, the synchronization signal management component150, and/or signal searching component 154, may be configured to searchfor or detect one or more synchronization signals based on thesynchronization numerology (identified at block 504) at the frequencyband (identified at block 502). In some examples, a synchronizationsignal may be a PSS, an SSS, or a signal transmitted on a PBCH.

At block 508, the method 500 may optionally include receiving the atleast one synchronization signal in a combined slot. In an aspect, forexample, along with one or more of the processors 912, the memory 916,the modem 140, and/or the transceiver 902, the synchronization signalmanagement component 150 may be configured to receive, via thetransceiver 902, one or more synchronization signals in a combined slot.In an example, the combined slot may include two or more slots withoutat least a downlink common burst or an uplink common burst between thetwo or more slots.

FIG. 6 is a flow diagram of an example method 600 of the presentdisclosure for synchronization channel design and signaling. The method600 may be performed by a UE 110 and more particularly by thesynchronization signal management component 150 described with referenceto FIGS. 1 and 9. For example, one or more of the processors 912, thememory 916, the modem 140, the synchronization signal managementcomponent 150, frequency band component 152, signal searching component154, synchronization numerology component 156, and/or frequency locationcomponent 158, may be configured to perform aspects of the method 600.

At block 602, the method 600 may include identifying a frequency bandsupported by a UE. In an aspect, for example, along with one or more ofthe processors 912, the memory 916, the modem 140, and/or thetransceiver 902, the synchronization signal management component 150,and/or frequency band component 152 may be configured to determine oridentify a frequency band supported by the UE 110.

At block 604, the method 600 may include identifying one or morefrequency locations based on the identified frequency band, wherein theone or more frequency locations are a subset of synchronization rasterpoints used for synchronization signal transmission. In an aspect, forexample, along with one or more of the processors 912, the memory 916,the modem 140, and/or the transceiver 902, the synchronization signalmanagement component 150, frequency band component 152, and/or frequencylocation component 158 may be configured to determine or identify one ormore frequency locations based on the frequency band determined at block602. In an example, the one or more frequency locations are in a subsetof synchronization raster points used for synchronization signaltransmission.

At block 606, the method 600 may include searching for at least onesynchronization signal based on the one or more identified frequencylocations. In an aspect, for example, along with one or more of theprocessors 912, the memory 916, the modem 140, and/or the transceiver902, the synchronization signal management component 150, signalsearching component 154, and/or frequency location component 158 may beconfigured to search for one or more synchronization signals based onthe one or more frequency locations that are determined or identified atblock 604. In some examples, a synchronization signal may be a PSS, anSSS, or a signal transmitted on a PBCH.

FIG. 7 is a flow diagram of an example method 700 of the presentdisclosure for synchronization channel design and signaling. The method700 may be performed by a base station 105 and more particularly by thesynchronization management component 170 described with reference toFIGS. 1 and 10. For example, one or more of the processors 1012, thememory 1016, the modem 160, the synchronization management component170, frequency band component 172, synchronization numerology component174, and/or frequency location component 176, may be configured toperform aspects of the method 700.

At block 702, the method 700 may include identifying a frequency band ina subset of frequency bands supported by a UE. In an aspect, forexample, along with one or more of the processors 1012, the memory 1016,the modem 160, and/or the transceiver 1002, the synchronizationmanagement component 170, and/or frequency band component 172 may beconfigured to identify or determine a frequency band in a subset offrequency bands that are supported by the UE 110.

At block 704, the method 700 may include identifying a synchronizationnumerology used for the subset of frequency bands. In an aspect, forexample, along with one or more of the processors 1012, the memory 1016,the modem 160, and/or the transceiver 1002, the synchronizationmanagement component 170, frequency band component 172, and/orsynchronization numerology component 174 may be configured to identify asynchronization numerology used for the frequency band identified atblock 702 and/or the subset of frequency bands supported by the UE 110.

At block 706, the method 700 may include transmitting at least onesynchronization signal having the identified synchronization numerologyat the identified frequency band. In an aspect, for example, along withone or more of the processors 1012, the memory 1016, the modem 160,and/or the transceiver 1002, the synchronization management component170 may be configured to transmit, via the transceiver 1002, one or moresynchronization signals based on the synchronization numerology(identified at block 704) at the frequency band (identified at block702). In some examples, a synchronization signal may be a PSS, an SSS,or a signal transmitted on a PBCH. In some cases, the at least onesynchronization signal is transmitted in a combined slot. In an aspect,for example, along with one or more of the processors 1012, the memory1016, the modem 160, and/or the transceiver 1002, the synchronizationmanagement component 170 may be configured to transmit, via thetransceiver 1002, one or more synchronization signals in a combinedslot. In an example, the combined slot may include two or more slotswithout at least a downlink common burst or an uplink common burstbetween the two or more slots.

FIG. 8 is a flow diagram of an example method 800 of the presentdisclosure for synchronization channel design and signaling. The method800 may be performed by base station 105 and more particularly by thesynchronization management component 170 described with reference toFIGS. 1 and 10. For example, one or more of the processors 1012, thememory 1016, the modem 160, the synchronization management component170, frequency band component 172, synchronization numerology component174, and/or frequency location component 176, may be configured toperform aspects of the method 800.

At block 802, the method 800 may include identifying a frequency bandsupported by a UE. In an aspect, for example, along with one or more ofthe processors 1012, the memory 1016, the modem 160, and/or thetransceiver 1002, the synchronization management component 170, and/orfrequency band component 172 may be configured to determine or identifya frequency band supported by the UE 110.

At block 804, the method 800 may include identifying one or morefrequency locations based on the identified frequency band, wherein theone or more frequency locations are a subset of synchronization rasterpoints used for synchronization signal transmission. In an aspect, forexample, along with one or more of the processors 1012, the memory 1016,the modem 160, and/or the transceiver 1002, the synchronizationmanagement component 170, frequency band component 172, and/or frequencylocation component 176 may be configured to determine or identify one ormore frequency locations based on the frequency band determined at block802. In an example, the one or more frequency locations are in a subsetof synchronization raster points used for synchronization signaltransmission.

At block 806, the method 800 may include transmitting at least onesynchronization signal based on the one or more identified frequencylocations. In an aspect, for example, along with one or more of theprocessors 1012, the memory 1016, the modem 160, and/or the transceiver1002, the synchronization management component 170, and/or frequencylocation component 176 may be configured to transmit, via thetransceiver 1002, one or more synchronization signals based on (or over)the one or more frequency locations that are determined or identified atblock 804. In some examples, a synchronization signal may be a PSS, anSSS, or a signal transmitted on a PBCH.

For purposes of simplicity of explanation, the methods discussed hereinare shown and described as a series of acts, it is to be understood andappreciated that the method (and further methods related thereto) is/arenot limited by the order of acts, as some acts may, in accordance withone or more aspects, occur in different orders and/or concurrently withother acts from that shown and described herein. For example, it is tobe appreciated that a method could alternatively be represented as aseries of interrelated states or events, such as in a state diagram.Moreover, not all illustrated acts may be required to implement a methodin accordance with one or more features described herein.

Referring to FIG. 9, one example of an implementation of UE 110 mayinclude a variety of components, some of which have already beendescribed above, but including components such as one or more processors912 and memory 916 and transceiver 902 in communication via one or morebuses 944, which may operate in conjunction with modem 140 andsynchronization signal management component 150 to enable one or more ofthe functions described herein related to identifying thesynchronization signal location in a frequency band. Further, the one ormore processors 912, modem 140, memory 916, transceiver 902, RF frontend 988 and one or more antennas 986, may be configured to support voiceand/or data calls (simultaneously or non-simultaneously) in one or moreradio access technologies.

In an aspect, the one or more processors 912 may include a modem 140that uses one or more modem processors. The various functions related tosynchronization signal management component 150 may be included in modem140 and/or processors 912 and, in an aspect, can be executed by a singleprocessor, while in other aspects, different ones of the functions maybe executed by a combination of two or more different processors. Forexample, in an aspect, the one or more processors 912 may include anyone or any combination of a modem processor, or a baseband processor, ora digital signal processor, or a transmit processor, or a receiverprocessor, or a transceiver processor associated with transceiver 902.In other aspects, some of the features of the one or more processors 912and/or modem 140 associated with synchronization signal managementcomponent 150 may be performed by transceiver 902.

Also, memory 916 may be configured to store data used herein and/orlocal versions of applications 975 or synchronization signal managementcomponent 150 and/or one or more of its subcomponents being executed byat least one processor 912. Memory 916 can include any type ofcomputer-readable medium usable by a computer or at least one processor912, such as random access memory (RAM), read only memory (ROM), tapes,magnetic discs, optical discs, volatile memory, non-volatile memory, andany combination thereof. In an aspect, for example, memory 916 may be anon-transitory computer-readable storage medium that stores one or morecomputer-executable codes defining synchronization signal managementcomponent 150 and/or one or more subcomponents, and/or data associatedtherewith, when UE 110 is operating at least one processor 912 toexecute synchronization signal management component 150 and/or one ormore subcomponents.

In an aspect, for example, the one or more processors 912 may include amodem 140 that uses one or more modem processors. The various functionsrelated to synchronization channel design and signaling may be includedin modem 140 and/or processors 912 and, in an aspect, may be executed bya single processor, while in other aspects, different ones of thefunctions may be executed by a combination of two or more differentprocessors. For example, in an aspect, the one or more processors 912may include any one or any combination of a modem processor, or abaseband processor, or a digital signal processor, or a transmitprocessor, or a transceiver processor associated with transceiver 902.In particular, the one or more processors 912 may implement componentsincluded in the synchronization signal management component 150,frequency band component 152, signal searching component 154,synchronization numerology component 156, and/or frequency locationcomponent 158.

Transceiver 902 may include at least one receiver 906 and at least onetransmitter 908. Receiver 906 may include hardware, firmware, and/orsoftware code executable by a processor for receiving data, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). Receiver 906 may be, for example, a radiofrequency (RF) receiver. In an aspect, receiver 906 may receive signalstransmitted by at least one base station 105. Additionally, receiver 906may process such received signals, and also may obtain measurements ofthe signals, such as, but not limited to, Ec/Io, SNR, RSRP, RSSI, etc.Transmitter 908 may include hardware, firmware, and/or software codeexecutable by a processor for transmitting data, the code comprisinginstructions and being stored in a memory (e.g., computer-readablemedium). A suitable example of transmitter 908 may including, but is notlimited to, an RF transmitter.

Moreover, in an aspect, UE 110 may include RF front end 988, which mayoperate in communication with one or more antennas 965 and transceiver902 for receiving and transmitting radio transmissions, for example,wireless communications transmitted by at least one base station 105 orwireless transmissions transmitted by UE 110. RF front end 988 may beconnected to one or more antennas 965 and can include one or morelow-noise amplifiers (LNAs) 990, one or more switches 992, one or morepower amplifiers (PAs) 998, and one or more filters 996 for transmittingand receiving RF signals.

In an aspect, LNA 990 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 990 may have a specified minimum andmaximum gain values. In an aspect, RF front end 988 may use one or moreswitches 992 to select a particular LNA 990 and its specified gain valuebased on a desired gain value for a particular application.

Further, for example, one or more PA(s) 998 may be used by RF front end988 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 998 may have specified minimum and maximumgain values. In an aspect, RF front end 988 may use one or more switches992 to select a particular PA 998 and its specified gain value based ona desired gain value for a particular application.

Also, for example, one or more filters 996 can be used by RF front end988 to filter a received signal to obtain an input RF signal. Similarly,in an aspect, for example, a respective filter 996 can be used to filteran output from a respective PA 998 to produce an output signal fortransmission. In an aspect, each filter 996 can be connected to aspecific LNA 990 and/or PA 998. In an aspect, RF front end 988 can useone or more switches 992 to select a transmit or receive path using aspecified filter 996, LNA 990, and/or PA 998, based on a configurationas specified by transceiver 902 and/or processor 912.

As such, transceiver 902 may be configured to transmit and receivewireless signals through one or more antennas 965 via RF front end 988.In an aspect, transceiver may be tuned to operate at specifiedfrequencies such that UE 110 can communicate with, for example, one ormore base stations 105 or one or more cells associated with one or morebase stations 105. In an aspect, for example, modem 140 can configuretransceiver 902 to operate at a specified frequency and power levelbased on the UE configuration of the UE 110 and the communicationprotocol used by modem 140.

In an aspect, modem 140 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 902 such that thedigital data is sent and received using transceiver 902. In an aspect,modem 140 can be multiband and be configured to support multiplefrequency bands for a specific communications protocol. In an aspect,modem 140 can be multimode and be configured to support multipleoperating networks and communications protocols. In an aspect, modem 140can control one or more components of UE 110 (e.g., RF front end 988,transceiver 902) to enable transmission and/or reception of signals fromthe network based on a specified modem configuration. In an aspect, themodem configuration can be based on the mode of the modem and thefrequency band in use. In another aspect, the modem configuration can bebased on UE configuration information associated with UE 110 as providedby the network during cell selection and/or cell reselection.

Referring to FIG. 10, one example of an implementation of a base station105 may include a variety of components, some of which have already beendescribed above, but including components such as one or more processors1012 and memory 1016 and transceiver 1002 in communication via one ormore buses 1044, which may operate in conjunction with modem 160 andsynchronization management component 170 to enable one or more of thefunctions described herein, for example, related to identifying thesynchronization signal locations or channel raster in a frequency band.Further, the one or more processors 1012, modem 160, memory 1016,transceiver 1002, RF front end 1088 and one or more antennas 1065, maybe configured to support voice and/or data calls (simultaneously ornon-simultaneously) in one or more radio access technologies.

In an aspect, the one or more processors 1012 may include a modem 160that uses one or more modem processors. The various functions related tosynchronization management component 170 may be included in modem 160and/or processors 1012 and, in an aspect, can be executed by a singleprocessor, while in other aspects, different ones of the functions maybe executed by a combination of two or more different processors. Forexample, in an aspect, the one or more processors 1012 may include anyone or any combination of a modem processor, or a baseband processor, ora digital signal processor, or a transmit processor, or a receiverprocessor, or a transceiver processor associated with transceiver 1002.In other aspects, some of the features of the one or more processors1012 and/or modem 160 associated with synchronization managementcomponent 170 may be performed by transceiver 1002.

Also, memory 1016 may be configured to store data used herein and/orlocal versions of applications 1075 or synchronization managementcomponent 170 and/or one or more of its subcomponents being executed byat least one processor 1012. Memory 1016 can include any type ofcomputer-readable medium usable by a computer or at least one processor1012, such as random access memory (RAM), read only memory (ROM), tapes,magnetic discs, optical discs, volatile memory, non-volatile memory, andany combination thereof. In an aspect, for example, memory 1016 may be anon-transitory computer-readable storage medium that stores one or morecomputer-executable codes defining synchronization management component170 and/or one or more subcomponents, and/or data associated therewith,when base station 105 is operating at least one processor 1012 toexecute synchronization management component 170 and/or one or moresubcomponents.

In an aspect, for example, the one or more processors 1012 may include amodem 160 that uses one or more modem processors. The various functionsrelated to synchronization channel design and signaling may be includedin modem 160 and/or processors 1012 and, in an aspect, may be executedby a single processor, while in other aspects, different ones of thefunctions may be executed by a combination of two or more differentprocessors. For example, in an aspect, the one or more processors 1012may include any one or any combination of a modem processor, or abaseband processor, or a digital signal processor, or a transmitprocessor, or a transceiver processor associated with transceiver 1002.In particular, the one or more processors 1012 may implement componentsincluded in the synchronization management component 170, frequency bandcomponent 172, synchronization numerology component 174, and/orfrequency location component 176.

Transceiver 1002 may include at least one receiver 1006 and at least onetransmitter 1008. Receiver 1006 may include hardware, firmware, and/orsoftware code executable by a processor for receiving data, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). Receiver 1006 may be, for example, a RFreceiver. In an aspect, receiver 1006 may receive signals transmitted byat least one UE 110. Additionally, receiver 1006 may process suchreceived signals, and also may obtain measurements of the signals, suchas, but not limited to, Ec/Io, SNR, RSRP, RSSI, etc. Transmitter 1008may include hardware, firmware, and/or software code executable by aprocessor for transmitting data or synchronization signals, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). A suitable example of transmitter 1008 mayincluding, but is not limited to, an RF transmitter.

Moreover, in an aspect, the base station 105 may include RF front end1088, which may operate in communication with one or more antennas 1065and transceiver 1002 for receiving and transmitting radio transmissions,for example, wireless communications received from at least one UE 110or wireless transmissions transmitted to UE 110. RF front end 1088 maybe connected to one or more antennas 1065 and can include one or morelow-noise amplifiers (LNAs) 1090, one or more switches 1092, one or morepower amplifiers (PAs) 1098, and one or more filters 1096 fortransmitting and receiving RF signals.

In an aspect, LNA 1090 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 1090 may have a specified minimum andmaximum gain values. In an aspect, RF front end 1088 may use one or moreswitches 1092 to select a particular LNA 1090 and its specified gainvalue based on a desired gain value for a particular application.

Further, for example, one or more PA(s) 1098 may be used by RF front end1088 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 1098 may have specified minimum and maximumgain values. In an aspect, RF front end 1088 may use one or moreswitches 1092 to select a particular PA 1098 and its specified gainvalue based on a desired gain value for a particular application.

Also, for example, one or more filters 1096 can be used by RF front end1088 to filter a received signal to obtain an input RF signal.Similarly, in an aspect, for example, a respective filter 1096 can beused to filter an output from a respective PA 1098 to produce an outputsignal for transmission. In an aspect, each filter 1096 can be connectedto a specific LNA 1090 and/or PA 1098. In an aspect, RF front end 1088can use one or more switches 1092 to select a transmit or receive pathusing a specified filter 1096, LNA 1090, and/or PA 1098, based on aconfiguration as specified by transceiver 1002 and/or processor 1012.

As such, transceiver 1002 may be configured to transmit and receivewireless signals through one or more antennas 1065 via RF front end1088. In an aspect, transceiver may be tuned to operate at specifiedfrequencies such that the base station 105 can communicate with, forexample, one or more UE 110 or one or more cells associated with thebase stations 105. In an aspect, for example, modem 160 can configuretransceiver 1002 to operate at a specified frequency and power level andthe communication protocol used by modem 160.

In an aspect, modem 160 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 1002 such that thedigital data is sent and received using transceiver 1002. In an aspect,modem 160 can be multiband and be configured to support multiplefrequency bands for a specific communications protocol. In an aspect,modem 160 can be multimode and be configured to support multipleoperating networks and communications protocols. In an aspect, modem 160can control one or more components of the base station 105 (e.g., RFfront end 1088, transceiver 1002) to enable transmission and/orreception of signals from the UE 110 based on a specified modemconfiguration. In an aspect, the modem configuration can be based on themode of the modem and the frequency band in use.

The above detailed description set forth above in connection with theappended drawings describes examples and does not represent the onlyexamples that may be implemented or that are within the scope of theclaims. The term “example,” when used in this description, means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, computer-executable code or instructionsstored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with aspecially-programmed device, such as but not limited to a processor, adigital signal processor (DSP), an ASIC, a FPGA or other programmablelogic device, a discrete gate or transistor logic, a discrete hardwarecomponent, or any combination thereof designed to perform the functionsdescribed herein. A specially-programmed processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aspecially-programmed processor may also be implemented as a combinationof computing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on anon-transitory computer-readable medium. Other examples andimplementations are within the scope and spirit of the disclosure andappended claims. For example, due to the nature of software, functionsdescribed above can be implemented using software executed by aspecially programmed processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items prefaced by “at least one of” indicates a disjunctivelist such that, for example, a list of “at least one of A, B, or C”means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the common principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Furthermore, although elements of the describedaspects and/or embodiments may be described or claimed in the singular,the plural is contemplated unless limitation to the singular isexplicitly stated. Additionally, all or a portion of any aspect and/orembodiment may be utilized with all or a portion of any other aspectand/or embodiment, unless stated otherwise. Thus, the disclosure is notto be limited to the examples and designs described herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method of wireless communications, comprising:identifying, by a base station, a frequency band in a subset offrequency bands supported by a user equipment (UE); identifying, by thebase station, a synchronization numerology used for the subset offrequency bands; and transmitting, by the base station, at least onesynchronization signal having the identified synchronization numerologyat the identified frequency band.
 2. The method of claim 1, wherein thesynchronization numerology corresponding to the subset of frequencybands and the synchronization numerology corresponding to another subsetof frequency bands supported by the UE are different.
 3. The method ofclaim 1, wherein the synchronization numerology corresponding to thesubset of frequency bands and the synchronization numerologycorresponding to another subset of frequency bands supported by the UEare same.
 4. The method of claim 1, wherein the synchronizationnumerology is a data channel numerology or a control channel numerology.5. The method of claim 1, wherein the synchronization numerology is 15kHz or a multiple of 15 kHz.
 6. The method of claim 1, wherein thesynchronization signal is a Primary Synchronization Signal (PSS), aSecondary Synchronization Signal (SSS), or a signal transmitted on aPhysical Broadcast Channel (PBCH).
 7. The method of claim 1, whereintransmitting at least one synchronization signal comprises transmittingat least one synchronization signal in a combined slot.
 8. The method ofclaim 7, wherein the combined slot includes two or more slots without atleast a downlink common burst or an uplink common burst between the twoor more slots.
 9. A method of wireless communications, comprising:identifying, by a base station, a frequency band supported by a userequipment (UE); identifying, by the base station, one or more frequencylocations based on the identified frequency band, wherein the one ormore frequency locations are a subset of synchronization raster pointsused for synchronization signal transmission; and transmitting, by thebase station, at least one synchronization signal based on the one ormore identified frequency locations.
 10. The method of claim 9, whereinthe subset of synchronization raster points includes known frequencylocations to the UE.
 11. The method of claim 9, wherein the one or morefrequency locations comprises at least two frequency locations, andwherein a spacing between two frequency locations of the at least twofrequency locations is equal to or larger than a synchronization channelraster.
 12. The method of claim 9, wherein the frequency band is in asubset of frequency bands that are supported by the UE.
 13. The methodof claim 12, wherein the subset of the frequency bands only includesfrequency bands with a minimum system bandwidth.
 14. The method of claim12, wherein the subset of the frequency bands only includes frequencybands with a same synchronization bandwidth upper boundary.
 15. Themethod of claim 12, wherein each frequency band of the subset of thefrequency bands has a known synchronization numerology.
 16. The methodof claim 12, wherein the subset of the frequency bands includesfrequency bands having at least one known synchronization channelraster.
 17. The method of claim 9, wherein the subset of synchronizationraster points includes synchronization raster points having asynchronization channel raster corresponding to a known decimationfactor.
 18. The method of claim 9, wherein the synchronization signal isa Primary Synchronization Signal (PSS), a Secondary SynchronizationSignal (SSS), or a signal transmitted on a Physical Broadcast Channel(PBCH).
 19. A base station for wireless communications, comprising: atransceiver; a memory configured to store instructions; and at least oneprocessor communicatively coupled with the memory and the transceiver,wherein the at least one processor is configured to execute theinstructions to: identify a frequency band in a subset of frequencybands supported by the apparatus; identify a synchronization numerologyused for the subset of frequency bands; and transmit, via thetransceiver, at least one synchronization signal having the identifiedsynchronization numerology at the identified frequency band.
 20. Thebase station of claim 19, wherein the synchronization numerologycorresponding to the subset of frequency bands and the synchronizationnumerology corresponding to another subset of frequency bands supportedby the UE are different.
 21. The base station of claim 19, wherein thesynchronization numerology corresponding to the subset of frequencybands and the synchronization numerology corresponding to another subsetof frequency bands supported by the UE are same.
 22. The base station ofclaim 19, wherein the transmit at least one synchronization signalcomprises transmit at least one synchronization signal in a combinedslot.
 23. The base station of claim 22, wherein the combined slotincludes two or more slots without at least a downlink common burst oran uplink common burst between the two or more slots.
 24. A base stationfor wireless communications, comprising: a transceiver; a memoryconfigured to store instructions; and at least one processorcommunicatively coupled with the memory, wherein the at least oneprocessor is configured to execute the instructions to: identify afrequency band supported by the apparatus; identify one or morefrequency locations based on the identified frequency band, wherein theone or more frequency locations are a subset of synchronization rasterpoints used for synchronization signal transmission; and transmit, viathe transceiver, at least one synchronization signal based on the one ormore identified frequency locations.
 25. The base station of claim 24,wherein the subset of synchronization raster points includes knownfrequency locations to the UE.
 26. The base station of claim 24, whereinthe one or more frequency locations comprises at least two frequencylocations, and wherein a spacing between two frequency locations of theat least two frequency locations is equal to or larger than asynchronization channel raster.
 27. The base station of claim 24,wherein the frequency band is in a subset of frequency bands that aresupported by the apparatus.
 28. The base station of claim 27, whereinthe subset of the frequency bands only includes frequency bands with aminimum system bandwidth.
 29. The base station of claim 27, wherein eachfrequency band of the subset of the frequency bands has a knownsynchronization numerology.
 30. The base station of claim 27, whereinthe subset of the frequency bands includes frequency bands having atleast one known synchronization channel raster.